摘要
天波超视距雷达(over-the-horizon radar,OTHR)中,机动目标信号存在频谱扩展,导致目标检测性能下降。强的海杂波进一步增加了机动目标的检测难度。针对该问题,考虑到海杂波信号能量主要集中在零频附近,而且可以建模为一个自回归(auto-regressive,AR)过程,用AR滤波器抑制海杂波;考虑到机动目标信号近似为线性调频信号,而分数阶傅里叶变换(fractional Fourier transform,FRFT)能有效积累线性调频信号的能量,因此采用FRFT算法估计目标运动参数,实现机动目标检测;在此基础上用分级迭代的FRFT进一步降低运算量;针对多目标检测问题,用"CLEAN"方法逐个检测机动目标。仿真结果表明,与已有的离散多项式变换(discrete polynomial transform,DPT)算法相比,本文算法可以更好地适用于多目标检测;与Radon-Wigner变换算法相比,本文算法可以达到更高的参数估计精度。
In the over-the-horizon radar （OTHR）,the Doppler spread in the maneuvering target echo re-duces the detection performance.The strong sea clutter further increases the detection difficulty.Considering that the sea clutter is mainly near zero frequency and can be modeled as an auto-regressive （AR）process,an AR filter has been used to suppress the sea clutter.Considering that fractional Fourier transform （FRFT）can effec-tively concentrate chirp signals,and the maneuvering target signal is approximately a chirp signal,the FRFT-based method has been applied in the maneuvering target detection and parameter estimation.The grading itera-tive method is used for fast calculation,and the shading problem between multiple targets is solved through the“CLEAN”method.The proposed algorithm can be better applicable to multi-target detection compared with the discrete polynomial transform （DPT）method,and has higher parameter estimation accuracy than the Radon-Wigner transform （RWT）method.Simulation results show that the proposed algorithm improves the maneuve-ring detection ability of OTHR,and can estimate the parameter of the target more accurately.
出处
《系统工程与电子技术》
EI
CSCD
北大核心
2014年第9期1725-1730,共6页
Systems Engineering and Electronics
基金
国家自然科学基金重点项目(61032010
61371184
61101172)
中央高校基本科研业务费专项资金(ZYGX2012J018)资助课题
关键词
天波超视距雷达
机动目标检测
海杂波抑制
分级迭代分数阶傅里叶变换
over-the-horizon radar（OTHR）
maneuvering target detection
sea clutter suppression
grad-ing iterative fractional Fourier transform （FRFT）
